An aneurysm is a dilation of a vessel, such as blood vessel, that may pose a risk to a patient's health due from rupture, clotting, or dissecting. For example, rupture of an aneurysm in a patient's brain may cause a stroke, and lead to brain damage and death. Cerebral aneurysms may be detected in a patient, e.g., following seizure or hemorrhage, and may be treated by applying vaso-occlusive devices, such as coils or stents. Coils that may be used to fill or embolize neurological aneurysms are typically made from platinum, and tend to be small coils or springs which can be shaped into a secondary shape of a more complex curve in order to help fill the aneurysm body. Unfortunately, currently used and proposed occlusive devices are difficult to position and remove, and present a risk of migration and resulting harm to the patient, particularly if they become dislodged from the site of insertion.
One type of neurovascular embolization stent coil device that has been proposed includes a central coil (e.g., metal coil) with a woven and/or braid material connected to the device. See, e.g., U.S. Pat. No. 7,749,242 (“the '242 patent”), which describes an expanding vaso-occlusive device including an expandable member attached to a central inner member on both ends of the expandable member but includes an internal “stop” attached to the central inner member. Similarly, U.S. Pat. No. 5,382,259 (“the '259 patent”) describes vasoocclusion devices that may include a fibrous, woven or braided covering. Both the '259 patent and the '242 patent require that the woven, expandable outer members be relatively short and limited in expandability, otherwise they are difficult (if not impossible) to push and/or retrieve to/from a cannula. Unfortunately, small (short) coils are less desirable. Aneurysms with larger mouths are very difficult to treat, particularly with small and relatively thin coils. The coils may slip back out of the aneurysm sack. In addition, procedures using such small, thin, coils may require a longer and more involved procedure. For example, a 7 mm diameter neurological aneurysm may typically be filled with five to seven individual spring shaped coils, resulting in a longer and more complicated procedure than if the number of devices was reduced.
Described herein are braid-stent coil structures in which an expandable braided portion (which may be very long, e.g., 5 cm and longer) is connected to a pushable/pullable metal coil; the metal coil may provide a pushable core that may be used to position the braided expandable member. In the embodiments described herein, the tubular braided region may be fixed to the metal coil at only a single position, and be of great length and have an expanded diameter that is much larger than the diameter of the push coil, while still allowing the device to be pushed to insert from a catheter and pulled to retrieve into a catheter.
In addition to the implants (vaso-occlusive apparatuses), there is also a need for tools, including deployment tools, for deploying such devices. Accordingly, a deployment tool for delivering a soft, long stent-coil or other embolic device is desired. A deployment tool that can prevent longitudinal structural failure, buckling, and locking of the embolic device in the deployment catheter is also desired. A deployment tool that can retract and reposition the embolic device in the catheter is also desired. In addition to solutions for delivering a soft, long stent-coil which includes an inner core member such as a coil, a deployment tools is also desired to easily deploy, retrieved and detach a long, soft stent which has no core member.